Week 4

Exercises on JOOS

The purpose of these exercises is to help you get comfortable with the
JOOS development environment and to improve the quality of the JOOS
benchmarks you write for Milestone 3.

Write 3 tiny JOOS programs:

The first simply prints "Hello World!".

Another sorts a list of integers given on stdin and writes the sorted
list to stdout.

A final program sorts a list of words given on stdin by word frequency and
writes the top 10 words and their frequencies to stdout. Consider
only tokens matching [A-Za-z]+ as words and furthermore since
we're Unix people (right?) assume case matters. What are
the top 10 words and their frequencies in cs520/2007/public_html/index.html?

Motivation: 1.1 and 1.2 are there to help you figure out how to
do input and output in JOOS, and 1.3 is to help identify more problems
you might have in writing Java and JOOS programs.

Compile your 3 programs to Java bytecode with joosc and javac.
Disassemble them to Jasmin assembler with d-java. How do the sizes of
the .j files compare for each compiler? Use wc -l to measure them.

Motivation: understand the process by which joosc works (joos +
jasmin), and see how the bytecode generated by joos compares with that
generated by javac. Presumably you'll be interested enough to
summarily inspect the .j files as well.

Summarize the class hierarchy and containment relationships for
the AwtDemos/AllEvents.java program. Draw a (partial) call graph
starting from main(). Consider inheritance, containment, and calls
across library interfaces, but do not consider library implementation
details. You are encouraged to use dot to draw the call graph, it is
a powerful tool for drawing directed graphs quickly.

Motivation: The objective here is to improve literacy and work
on addressing any potential fear of "large"-ish programs; grep or
Eclipse and Google will probably help you to navigate and understand
the source code. If this question is taking too long, just give a
partial answer addressing some interesting part of the AllEvents.java
program.